The field of this invention is drug delivery systems. More specifically the field of this invention is fabrics or fibers that contain drugs or other chemicals for various purposes, and which deliver these substances outside the fabric or fiber at a later time for various purposes. Furthermore the invention includes a method for filling such chemicals into such fibers or fabrics.
In the past various drug delivery systems have been developed based on fibers that are made to contain drugs within the fiber. Under later conditions the drugs are released from the fibers and delivered to the environment around the fibers for various purposes. See for example U.S. Pat. No. 5,024,671, by Tu et al., and U.S. Pat. No. 4,801,458, by Hidaka et al. Both of these patents use porous fibers containing medication that deliver the medication rapidly through pores in the fibers. However these inventions have various drawbacks. It is difficult and expensive to make quality control checks on the porosity of the fibers, and therefore to their rate of delivery. Furthermore the consistent creation of pores in the fibers is almost impossible and sometimes requires chemical treatment of the fibers to create pores. This treatment results in severe physical degradation of the engineering properties of the fibers and makes it difficult or impossible to use the drug-bearing fiber to make a strength-bearing cloth. Therefore the fibers have to be incorporated into other strength-providing fibers in order to make fabrics. This complicates the manufacture of such items as vascular grafts and bandages.